The aim of this study is to determine the optimization of enzymatic protein hydrolysis conditions on the angiotensin-converting enzyme inhibitory (ACEI) activity of blood cockle meat. Preliminary study was carried out to evaluate the effect of different commercial proteinases (Alcalase®, Protamex™, Neutrase®, pepsin, papain, trypsin and α-chymotrypsin) and hydrolysis time on the ACEI activity of cockle’s meat. The proteinase with the highest ACEI activity will be used in the optimization study using Response Surface Methodology. A face-centered central composite design was employed to investigate the effect of hydrolysis conditions parameters (i.e hydrolysis time, pH, hydrolysis temperature and enzyme to substrate (E/S) ratio) towards ACEI activity of cockle’s meat. Preliminary study found that the highest ACEI activity was given by Protamex™ at 6 hrs. Therefore, optimization study was carried out using Protamex™ at 4-8 hrs hydrolysis times with temperature of 35-60oC, pH of 5.5- 7.5 and E/S of 0.5-1.5%. All variables were successfully fitted with the quadratic model (p < 0.0001) with a non-significant lack-of-fit (p = 0.3665), and also possess good coefficient of determination (p = 0.8666) and adjusted R-square (p = 0.8158). The optimum hydrolysis conditions were found to be at temperature of 59.8o C, time of 4.69 hrs, pH of 5.59 and E/S ratio of 0.9%. ACEI activity of the experimental value (97.8%) agreed with the predicted value (99.2%) within 95% confidence interval.